1886. | BOTANICAL GAZETTE. 51 
in true ferns. In the latter this remains permanent, so that the 
root-cap consists of a series of distinct strata or lamelle, each 
composed of a single layer of cells, and representing a single 
segment of the apical cell; but in Botrychium walls are soon 
formed in all directions, and thus the original strata become so 
merged as to obliterate completely the boundaries between them. 
In the lateral segments there are formed for some time walls 
perpendicular to the broad faces only of the segments, so that 
the latter remain for some time single layers of cells, the growth 
of the segments being almost entirely lateral, and the vegetative 
cone is thus rendered very obtuse. The first transverse walls are 
formed in the outer cells, where they continue to form rapidly, 
alternating with longitudinal walls and forming a small-celled 
tissue whose cells are nearly cubical in form. Division does not 
pheral protoplasm of the cells contain numerous granules. 
The root soon reaches nearly its full diameter, any further 
growth being due to increase in the size of the cells, and longi- 
tudinal divisions cease, although for some time transverse walls 
form rapidly except in the procambium cells. These finally 
cease and the subsequent lengthening of the root is due to the 
elongation of its cells. 
The epidermal cells become thicker walled, the walls at the 
Same time becoming brown, and the cells losing the greater part 
or all of their contents. 
_ The ground-tissue cells remain distinguishable into two por- 
tions, although this is not so evident as in the younger parts 
oF the root. They develop great quantities of starch in sm ll, 
roundish or oval granules, these being especially numerous in 
the larger celled inner parenchyma. 
